Various foodstuffs, liquids, and other degradable material can be sterilely packaged in pouch-type flexible containers made from webs of flexible film that are folded and sealed together along the peripheral side edges. This type of flexible packaging is commonly referred to as a form, fill, and seal package. There are a number of advantages to these pouch-type flexible containers, including low weight, durability, and low cost fabrication. Some medical solutions have also been sterilely packaged in pouch-type flexible containers of the form, fill, and seal type.
One disadvantage of these pouch-type flexible containers for medical solution use is that it is difficult to make a sterile connection to the flexible container for withdrawing the contents in a sterile manner. The wall material of the container is flexible and lacks rigidity. Thus it is difficult to obtain a liquid-tight and leakproof connection through the flexible wall using traditional medical connectors such as needles or piercing pins.
Traditionally, it has been necessary for flexible solution containers used for parenteral solutions to include administration ports to facilitate sterile and liquid-tight access to the solution. These pre-formed, administration ports are often molded from a suitable medical grade thermoplastic material. The usual considerations for the material employed in the administration ports are the ease of molding and the capability to be securely bonded to the flexible film walls of the container. For example, a "boat" administration port may be sealed (by known thermal bonding processes) between the two opposed sides or walls of the flexible film container so as to form a flexible solution container with an administration port. Ultrasonic welding or solvent bonding may also be used to seal the boat port to the container.
The majority of flexible films used for flexible solution containers are monolayer PVC films. Recently, some multiple-layer, extrusion-laminated or adhesive-laminated films have been used in form, fill, and seal packaging for fabricating flexible solution containers. The inner, solution-contacting film layer must be substantially inert to the solution. Also, the inner layer of the film must be readily bondable to itself when it folded over. Furthermore, the outer layer of the film must be bondably compatible with the plastic material used for the attachable administration port. The outer layer of the laminated film must be durable and also compatible with other materials that may contact, or be attached to, the outside surface. If neither the inner nor outer layer has the desired solution-maintaining characteristics and barrier characteristics, such as a low moisture and/or low oxygen permeability, then additional film layers may be required between the inner and outer layers.
A primary disadvantage of known flexible solution containers which include the above-described inserted port construction is that the port material typically has a higher oxygen permeability than the film material; that is, the port structure can be characterized as acting like a "hole" in the sealed bag material. The permeability characteristic of the port material is much greater than the permeability characteristic of the laminated film used to make the flexible container. Thus, the administration port of known flexible solution containers is often the weakest part of the barrier function of the container. This factor becomes extremely important for certain medical solutions which are sensitive (i.e., deleteriously affected by) oxygen or other penetrating gases, for example.
In the past, attempts to overcome the above-discussed deficiencies have been made by overwrapping the flexible solution container, and/or the administration ports, with a low permeability overwrap material. While this redundancy in packaging may provide the desired barrier characteristics, the overwrap material introduces two important disadvantages. First, there is the additional cost to fabricate, and later dispose of, the overwrap. Second, there is concern that extractables from the overwrap material may migrate into the contained solution during post-filling procedures, such as during a heat sterilization process or even during shelf life.
Pre-formed administration ports constitute potential places of leakage and are potential points of contaminant ingress in an otherwise sealed, durable, flexible container. Moreover, the ports make it more difficult to arrange an outer protective overwrap package around the flexible container. Also, the protective overwrap only initially prevents the packaged solution from losing its potency due to evaporation or diffusion. When the overwrap is removed or breached, the installed administration ports in the film essentially function as an undesirable breaches or "holes" in the barrier characteristics of the flexible container for certain sensitive drugs.
For example, due to the sensitivity of certain solutions to oxygen, such as amino acids, it is desirable to fabricate the flexible solution containers for the parenteral administration of these solutions from materials that minimize the permeation of oxygen. The gas permeation properties of the flexible container film can be easily controlled by the choice of film material(s) per se.
On the other hand, the oxygen permeation properties of materials conventionally used for the port structure per se typically do not have low oxygen permeation properties, and the gas permeation properties of such materials are not as easily controlled. Thus, it would be desirable to use the film, with its good gas barrier properties, to provide both the solution contacting surface and a pierceable diaphragm in the administration port system so that the poorer barrier properties of a conventional system material do not contribute to gas migration into or out of the flexible container. However, various known flexible containers having preformed, rigid port systems sealed between the film layers of the flexible container cannot function in such a manner.
Moreover, some known flexible container and administration port systems often include an entry port in addition to the administration port. The entry ports are likewise inserted between film layers at the container perimeter seal. Each port thus constitutes a breach or "hole" through an otherwise effective perimeter barrier.
A pierceable diaphragm can be provided in some administration ports to prevent an outflow of solution. During packaging, the flexible container may be filled through the entry port. After filling, the entry port is sealed, but the port, and specifically the exposed port material, is the potential weak point for compromising the barrier characteristics.
Flange ports are an alternative to inserted ports and may be advantageously sealed to a film surface. However, in many of flexible solution containers produced by known form, fill, and seal processes, the use of flange ports does not remove the barrier deficiency. Consider, for example, the flexible parenteral solution container that includes a flange-sealed port assembly as disclosed in U.S. Pat. No. 4,695,337 to Christine and in U.S. Pat. No. 4,779,397 to Christine et al. A major disadvantage of the disclosed flexible solution container is that the flexible film barrier of the flexible container is purposefully breached during the assembly steps to mount and seal the administration port or fitment to the inside surface of the flexible container, as seen, for example, in FIGS. 4a-4b of the patents.
Thus, due to the inherent breaches or "holes" in the film barriers of various known form, filled, and sealed flexible solution containers in current use, parenteral solutions may be subjected to degradation during the shelf life of the product solution. While an overwrap may provide some protection for the flexible container and for the port administration system from contamination or degradation during shelf life, the overwrap introduces additional concerns that manufacturers are increasingly seeking to avoid.
Thus, it would be desirable to utilize an unbreached and completely intact film in a form, filled, and sealed flexible solution container as the primary barrier for a medical solution packaged in a flexible solution container, and especially for certain oxygen-sensitive or other gas-sensitive parenteral solutions.
It would also be advantageous to provide a form, filled, and sealed flexible container having integral barrier characteristics without any compromises in the barrier characteristics of the film material used for the flexible solution container.
The Abbott Laboratories U.S. Pat. No. 5,334,180 discloses a sterile formed, filled, and sealed flexible solution container in which the container film defines a pierceable diaphragm that is sealed across the inlet end of an attached tubular port member 50. The film defines a U-shaped trough having a bottom surface 40 which includes a stretched fluid sump 30 and which is heat-sealed to a correspondingly shaped saddle flange 56 of the port member 50. A penetrator element or piercing element 60 is slidably disposed within the tubular port member and is adapted to be pushed inwardly by a conventional piercing pin so that the penetrator element reliably pierces the portion of the container wall film to which the tubular port member is sealed.
While this arrangement functions satisfactorily with various film materials and film wall designs, it would be desirable to provide an even more improved arrangement which could accommodate container films that have a very high resistance to penetration (owing, for example, to the composition of the film and/or to the thickness of the film). In particular, it would be beneficial if an improved design could be provided for establishing a very strong attachment seal of such penetration-resistant film to the tubular port member so as to reduce the likelihood that the film would merely stretch rather than be punctured and/or that the seal between the film and port member would fail as the penetrator element pushes against the diaphragm part of the film.
In addition, it would be desirable to provide an improved arrangement that could accommodate a wide variety of conventional piercing pins having different lengths so that the advancement of the penetrator element by the piercing pin would result in a minimum projection of the penetrator element into the container interior and thereby reduce the likelihood that the interior end of the penetrator element would damage, or otherwise contact, the adjacent sidewalls of the container.
It would also be beneficial to provide a form, filled, and sealed flexible container that includes an attached administration port system that is accessible by a variety of administration piercing pins, including center point pins, beveled pins, and blunt pins, and it would be beneficial to provide such a port system that is compatible with the various lengths and other dimensions of the most common of these administration pins.
It would also be desirable to provide a flexible container that allows the maximum amount of solution to be readily, completely, and easily delivered in a sterile manner from the container. To this end, an improved administration port system should be free of, or at least minimize, pockets or dam features that would prevent complete draining of the container through the port.
Finally, it would be desirable to provide an improved port administration system that can be readily attached to a flexible container with a high integrity seal and reduced distortion while also accommodating the location of the port along the fold of the container film.